1. Field of the Invention
The present invention relates to a lamination substrate and a manufacturing method.
2. Description of the Related Art
A liquid crystal display element has a structure in which a liquid crystal is held between a first substrate and a second substrate. The first substrate and the second substrate are laminated together using a sealing material. The liquid crystal is sealed in a space formed by the first substrate, the second substrate, and the sealing material. In an active matrix type liquid crystal display element, the first substrate is a thin film transistor (TFT) array substrate, and the second substrate is a counter substrate.
In a method of manufacturing a liquid crystal display element, a plurality of TFT array substrates is formed on a first mother substrate, and a plurality of counter substrates is formed on a second mother substrate. Then, the first and second mother substrates are cut, and whereby each of the TFT array substrates and the counter substrates is cut off.
Japanese Laid-open Patent Publication No. 9-141646 discloses a processing method for cutting a substrate of a liquid crystal display element. In the method of Japanese Laid-open Patent Publication No. 9-141646, a groove having a V-shaped cross section is formed on both surfaces of a base substrate (mother substrate) using a dicing blade (paragraph 0028). A out groove is formed along the V groove, and whereby the base substrate is cut. As a result, an individual piece substrate including a chamfered portion can be obtained.
However, in the method of Japanese Laid-open Patent Publication No. 9-141646, a base substrate is cut before substrates are laminated together. This makes it necessary to perform lamination for each individual piece substrate, and therefore, it is difficult to obtain a high productivity. A problem of a manufacturing method in which cutting is performed after first and second mother substrates are laminated together will be described below with reference to FIGS. 11 and 12. FIGS. 11 and 12 are cross-sectional views of steps of manufacturing a liquid crystal display element.
As illustrated in FIG. 11, a semiconductor wafer 110 and a mother glass substrate 120 are laminated together using a sealing material 130. The semiconductor wafer 110 includes a plurality of semiconductor substrates 100. FIG. 11 illustrates a structure in which the semiconductor wafer 110 includes two semiconductor substrates 100. The mother glass substrate 120 includes a plurality of counter substrates 101. FIG. 11 illustrates a structure in which the mother glass substrate 120 includes two counter substrates 101. A lamination substrate in which the send conductor substrate 100 and the counter substrate 101 are laminated together becomes a liquid crystal display element. The sealing material 130 is provided for each liquid crystal display element.
A liquid crystal 140 is sealed in a space formed by the semiconductor substrate 100, the counter substrate 101, and the sealing material 130. A terminal 113 for driving the liquid crystal 140 and a pixel electrode 111 are formed in the semiconductor substrate 100. First, the semiconductor wafer 110 is cut while the semiconductor wafer 110 and the mother glass substrate 120 are laminated together. That is, a notch groove 150 is formed between the semiconductor substrates 100 adjacent to each other.
Next, a scribe groove 160 is formed on a surface of the mother glass substrate 120 not facing the semiconductor wafer 110. As illustrated in FIG. 12, the lamination structure is disposed on a breaker stage 170 made of rigid urethane. A breaker squeegee 171 is disposed just above the scribe groove 160. Then, the breaker squeegee 171 is pushed in a direction of the mother glass substrate 120. As a result, the mother glass substrate 120 can be cut.
However, when the breaker squeegee 171 is pushed into the semiconductor substrate 100, the mother glass substrate 120 is pushed into the breaker stage 170. At this time, as illustrated in FIG. 12, the breaker stage 170 is deformed. By contact of the semiconductor substrate 100 with the mother glass substrate 120, corner portions of the semiconductor substrate 100 and the counter substrate 101 may be damaged (contact portion 181 in FIG. 12). In addition, by contact between the semiconductor substrates 100 adjacent to each other, the corner portions of the semiconductor substrate 100 may be damaged (contact portion 180 in FIG. 12). As described above, when the semiconductor substrate 100 or the counter substrate 101 is damaged, a fragment affects the terminal 113 or a circuit around the terminal 113. As a result, circuit failure or contact point failure of a connection terminal may be caused. Therefore, a yield may be lowered to degrade productivity.
In view of the above-described problem, an object of the present invention is to provide a lamination substrate having a high productivity and a method of manufacturing the lamination substrate.